" Copyright (c) 2014 Alex Yatskov <alex@foosoft.net>
"
" Permission is hereby granted, free of charge, to any person obtaining a copy of
" this software and associated documentation files (the "Software"), to deal in
" the Software without restriction, including without limitation the rights to
" use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
" the Software, and to permit persons to whom the Software is furnished to do so,
" subject to the following conditions:
"
" The above copyright notice and this permission notice shall be included in all
" copies or substantial portions of the Software.
"
" THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
" IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
" FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
" COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
" IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
" CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.


function! argwrap#validateRange(range)
    return len(a:range) > 0 && !(a:range.lineStart == 0 && a:range.colStart == 0 || a:range.lineEnd == 0 && a:range.colEnd == 0)
endfunction

function! argwrap#compareRanges(range1, range2)
    let [l:buffer, l:line, l:col, l:offset] = getpos('.')

    let l:lineDiff1 = a:range1.lineStart - l:line
    let l:colDiff1  = a:range1.colStart - l:col
    let l:lineDiff2 = a:range2.lineStart - l:line
    let l:colDiff2  = a:range2.colStart - l:col

    if l:lineDiff1 < l:lineDiff2
        return 1
    elseif l:lineDiff1 > l:lineDiff2
        return -1
    elseif l:colDiff1 < l:colDiff2
        return 1
    elseif l:colDiff1 > l:colDiff2
        return -1
    else
        return 0
    endif
endfunction

function! argwrap#findRange(braces)
    let [l:lineStart, l:colStart] = searchpairpos(a:braces[0], '', a:braces[1], 'Wnb')
    let [l:lineEnd,   l:colEnd]   = searchpairpos(a:braces[0], '', a:braces[1], 'Wcn')
    return {'lineStart': l:lineStart, 'colStart': l:colStart, 'lineEnd': l:lineEnd, 'colEnd': l:colEnd}
endfunction

function! argwrap#findClosestRange()
    let l:ranges = []
    for l:braces in [['(', ')'], ['\[', '\]'], ['{', '}']]
        let l:range = argwrap#findRange(braces)
        if argwrap#validateRange(l:range)
            call add(l:ranges, l:range)
        endif
    endfor

    if len(l:ranges) == 0
        return {}
    else
        return sort(l:ranges, 'argwrap#compareRanges')[0]
    endif
endfunction

function! argwrap#extractContainerArgText(range)
    let l:text = ''

    for l:lineIndex in range(a:range.lineStart, a:range.lineEnd)
        let l:lineText = getline(l:lineIndex)

        let l:extractStart = 0
        if l:lineIndex == a:range.lineStart
            let l:extractStart = a:range.colStart
        endif

        let l:extractEnd = strlen(l:lineText)
        if l:lineIndex == a:range.lineEnd
            let l:extractEnd = a:range.colEnd - 1
        endif

        if l:extractStart < l:extractEnd
            let l:extract = l:lineText[l:extractStart : l:extractEnd - 1]
            let l:extract = substitute(l:extract, '^\s\+', '', 'g')
            let l:extract = substitute(l:extract, ',$', ', ', 'g')
            let l:text .= l:extract
        endif
    endfor

    return l:text
endfunction

function! argwrap#updateScope(stack, char)
    let l:pairs  = {'"': '"', '''': '''', ')': '(', ']': '[', '}': '{'}
    let l:length = len(a:stack)

    if l:length > 0 && get(l:pairs, a:char, '') == a:stack[l:length - 1]
        call remove(a:stack, l:length - 1)
    elseif index(values(l:pairs), a:char) >= 0
        call add(a:stack, a:char)
    endif
endfunction

function! argwrap#trimArgument(text)
    return substitute(a:text, '^\s*\(.\{-}\)\s*$', '\1', '')
endfunction

function! argwrap#extractContainerArgs(text)
    let l:stack     = []
    let l:arguments = []
    let l:argument  = ''

    for l:index in range(strlen(a:text))
        let l:char = a:text[l:index]
        call argwrap#updateScope(l:stack, l:char)

        if len(l:stack) == 0 && l:char == ','
            call add(l:arguments, argwrap#trimArgument(l:argument))
            let l:argument = ''
        else
            let l:argument .= l:char
        endif
    endfor

    call add(l:arguments, argwrap#trimArgument(l:argument))
    return l:arguments
endfunction

function! argwrap#extractContainer(range)
    let l:textStart = getline(a:range.lineStart)
    let l:textEnd   = getline(a:range.lineEnd)

    let l:indent = matchstr(l:textStart, '\s*')
    let l:prefix = l:textStart[strlen(l:indent) : a:range.colStart - 1]
    let l:suffix = l:textEnd[a:range.colEnd - 1:]

    return {'indent': l:indent, 'prefix': l:prefix, 'suffix': l:suffix}
endfunction

function! argwrap#wrapContainer(range, container, arguments, style)
    let l:argCount = len(a:arguments)
    let l:line     = a:range.lineStart

    if a:style ==? 'default'
        call setline(l:line, a:container.indent . a:container.prefix)

        for l:index in range(l:argCount)
            let l:text = a:container.indent . a:arguments[l:index]
            if l:index < l:argCount - 1
                let l:text .= ','
            endif

            call append(l:line, l:text)
            let l:line += 1
            exec printf('%s>', l:line)
        endfor

        call append(l:line, a:container.indent . a:container.suffix)
    elseif a:style ==? 'bx'
        let l:lineText = a:container.indent . a:container.prefix
        if l:argCount > 0
            let l:lineText .= a:arguments[0]
            let l:arguments = a:arguments[1:]
            let l:argCount -= 1
        endif

        call setline(l:line, l:lineText)

        for l:index in range(l:argCount)
            let l:text = a:container.indent . ', ' . l:arguments[l:index]

            call append(l:line, l:text)
            let l:line += 1
            exec printf('%s>', l:line)
        endfor

        call append(l:line, a:container.indent . a:container.suffix)
        exec printf('%s>', l:line + 1)
    endif
endfunction

function! argwrap#unwrapContainer(range, container, arguments)
    let l:text = a:container.indent . a:container.prefix . join(a:arguments, ', ') . a:container.suffix
    call setline(a:range.lineStart, l:text)
    exec printf('silent %d,%dd_', a:range.lineStart + 1, a:range.lineEnd)
endfunction

function! argwrap#toggle(...)
    let l:style  = a:0 == 0 ? 'default' : 'bx'
    let l:cursor = getpos('.')

    let l:range = argwrap#findClosestRange()
    if !argwrap#validateRange(l:range)
        return
    endif

    let l:argText   = argwrap#extractContainerArgText(l:range)
    let l:arguments = argwrap#extractContainerArgs(l:argText)
    if len(l:arguments) == 0
        return
    endif

    let l:container = argwrap#extractContainer(l:range)
    if l:range.lineStart == l:range.lineEnd
        call argwrap#wrapContainer(l:range, l:container, l:arguments, l:style)
    else
        call argwrap#unwrapContainer(l:range, l:container, l:arguments)
    endif

    call setpos('.', l:cursor)
endfunction